Ultraviolet curable inks are presently in widespread industrial use for imprinting identifications, advertising messages, directions, and the like, on tubular articles, such as plastic bottles. One such apparatus for applying such ink to plastic or glass bottles or other articles is described, for example, in U.S. Pat. No. 3,766,851. After the ink has been imprinted on the bottle, the bottle is placed into curing apparatus in accordance with the prior art practice which subjects the ink to ultraviolet radiation. It is necessary for the entire peripheral surface of each bottle to be exposed to the ultraviolet radiation to assure that all the imprinted ink will be cured.
Accordingly, ultraviolet apparatus has been devised in the past to achieve that purpose. U.S. Pat. No. 3,840,999 (Re. 29,590), for example, provides such ultraviolet curing apparatus in which the articles are moved in succession along a pathway through a curing oven. An ultraviolet radiation-emitting lamp is mounted to direct ultraviolet radiation through the oven. The lamp radiates ultraviolet radiation primarily in one direction, and the articles are moved through the oven into and through the radiation field from the lamp. In order that the entire peripheral surface of each article may be exposed to the radiation from the lamp, the articles are rotated around their longitudinal axes as they are moved through the radiation. This is achieved by supporting the articles on mandrels which carry the articles through the oven and across the radiation field. At the same time, the mandrels are rotated so that each article may be turned in order to expose its entire peripheral surface to the ultraviolet radiation. This serves to assure that all the ink printings on the surface of each article may be properly cured.
Apparatus of the type described in U.S. Pat. No. 3,840,999, although well suited for its particular purpose, is relatively complex, and it is not readily adaptable to handle articles of different shapes and sizes. In fact, a complicated adjustment procedure must be followed to enable the apparatus of the patent to process articles of different shapes and sizes.
An object of the present invention is to provide an ultraviolet curing apparatus which is extremely simple and inexpensive in its construction, and which is capable of handling articles of a wide range of shapes and sizes with extremely simple adjustment requirements.